As a means for detecting file migration, Japanese Patent Laid-Open Publication No. 2005-010950 (Patent Document 1) discloses a file management device. This file management device creates a content list file for managing the logical structure of a group of content files, and detects migration of respective content files based on the registered information on the content list file.
Further, as a means for managing a group of files in which the generations thereof are managed, Japanese Patent Laid-Open Publication No. 10-293711 (Patent Document 2) discloses a master file generation management device. In this device, each file has applicable period information indicating the application start date and the application end date. Thereby, master file data in multiple generations having the same file name is managed.
[Patent Document 1] JP 2005-010950 A
[Patent Document 2] JP 10-293711 A
However, the art disclosed in Patent Documents 1 and 2 involves the following problems. In the file management device disclosed in Patent Document 1, as a range of detecting file migration is limited to the same file name, if the file name of a migrated file is changed from the file name before migration, it is handled as a different file. As such, in the case where a file name is changed when an event occurs and a new file is created with the same file name as that before the change (that is, rotation) such as the case of system logs of Linux (registered trademark), file migration cannot be detected. Accordingly, in the file management device of Patent Document 1, in the case of copying a group of files in which the generations thereof are managed by changes in the file names as described above, if rotation of files occurs during the copying, a problem will be caused in the copying process of the file group. As such, in the file management device of Patent Document 1, there have been cases where proper file management cannot be realized, including, the same file being copied for a plurality of times with different file names and some files remaining uncopied.
On the other hand, in the master file generation management device disclosed in Patent Document 2, a file group which is an object of generation management is a group of files having the same file name. Accordingly, there has been a problem that a file group including a plurality of files having different file names cannot be managed properly, so that rotation in such a file group cannot be detected. Further, as it is necessary to include applicable period information in respective files in order to manage the files, some files may not be managed. As such, this device lacks versatility.